Scalable video coding (SVC) and multi-view video coding (MVC) currently standardizing in MPEG/JVT (Joint Video Team) are based on H.264/AVC. The NALU format of H.264/AVC is used for packetization of encoded bitstream.
FIG. 1 shows conceptual structure of video coding layer (VCL) and network abstraction layer (NAL). As shown in FIG. 1, H.264/AVC is composed of the VCL which encodes moving pictures and the NAL which connects the VLC to lower system to transmit and store the encoded information. Independently of the bit stream generated by the VLC, there are sequence parameter set (SPS), picture parameter set (PPS), and supplemental enhancement information (SEI) for timing information for each picture, information for random access, and so on.
FIG. 2 is a block diagram which shows the NALU format proposed in the standard SVC. As shown in FIG. 2, a NALU includes a NAL header (NALH) and NAL payload. A NALH is 3-5 byte long and includes information about NAL type, layer identification information of video data in the payload (priority, spatial scalable level, temporal scalable level, and quality scalable level). The NAL type field includes F field, NRI (nal_ref_idc) indicating whether it is referenced picture or not, and indicator of NALU type. The layer identification information field includes priority field (P), dependency_id field (D) for spatial scalable level, temporal level field (T), and quality scalable level field (Q).
The same NALU format used in the SVC as in FIG. 2 is also used for the MVC. Instead of the layer identification information, view identification information is included.
According to the NALU format of the current SVC and MVC, all the layer identification information and the view identification information should be parsed to identify layer or view number. Especially, in order to identify layer in the SVC, 2-4 byte long layer identification information should be parsed into P, D, T, and Q values, so that this processing imposes burden to processors and increases cost of system.
The NALH has layer identification information, which the routers in the network including the IPv6 routers are not expected to parse. For as shown FIG. 13, the NALH is located in the payload of an IP packet. It is required to put the information into IP header which is read by the routers. The method how to render label has not been standardized yet. If one can identify packet priority, QoS (Quality of Service) control becomes easier so that upon congestion, less important packets can be discarded.
FIG. 3 shows procedure to identify layer of arbitrary NALU by parsing whole NALH according to the NALU format of the conventional SVC standard so that it is a flow chart to show for the MANE (media aware network element) to decide whether it forwards or discards each NALU.
The MANE in FIG. 3 parses P, D, T, and Q values (S11) from each NALU (which is generated by the encoder or transmitted over wired or wireless networks) and, then, parsed P, D, T, and Q values are compared to pre-defined values (p, d, t, q) in order for the MANE to decide whether it forwards or discards each NALU (S12). If any one of the value does not meet the requirement, the NALU is discarded (S13) while the NALU which satisfies all requirements is extracted and forwarded to the decoder (S14).
Burden of processors during extraction process of NALUs is applied to the decoding process in the same way so that the decoder parses P, D, T, and Q values from every NALU delivered through wired or wireless networks or stored. The values are evaluated if the layer of the NALU is included in layers which the decoder is to decode. Only when the values satisfy the requested setting points, the NALU is decoded, otherwise the NALU is discarded.